A portion of the disclosure of this patent document contains material to which a claim of copyright protection is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all other rights whatsoever.
1. Field of the Invention
The invention relates to bar code reading and in particular to a new bar code or symbol with structure and features that make it particularly suitable for consumer-scanning applications. Its features include a user-recognizable graphic pattern located within the symbol, at least a portion of which is machine read able and recognizable by a symbol decoder.
2. Background of the Invention
Bar code symbols are formed from bars and spaces, such elements being typically rectangular in shape with a variety of possible widths. The specific arrangement of elements defines characters represented according to a set of rules and definitions specified by the code or xe2x80x9csymbologyxe2x80x9d used. The relative size of the bars and spaces is determined by the type of coding used, as is the actual size of the bars and spaces. The number of characters (represented by the bar code symbol) is referred to as the density of the symbol. To encode a desired sequence of the characters, a collection of element arrangements is concatenated together to form a complete bar code symbol, with each character of the symbol being represented by its own corresponding group of elements. In some symbologies, a unique xe2x80x9cstartxe2x80x9d and xe2x80x9cstopxe2x80x9d character is used to indicate when the bar code begins and ends. A number of different bar code symbologies is in widespread use, including UPC/EAN, Code 39, Code 128, Codeabar, and Interleaved 2 of 5.
In order to increase the amount of data that can be represented or stored on a given amount of surface area, several more compact bar code symbologies have been developed. One of these code standards, Code 49, exemplifies a xe2x80x9ctwo-dimensionalxe2x80x9d symbol by reducing the vertical height of a one-dimensional symbol, and then stacking distinct rows of such one-dimensional symbols, so that information is encoded both vertically as well as horizontally. That is, in Code 49, there are several rows of bar and space patterns, instead of only one row as in a one-dimensional symbol. The structure of Code 49 is described in U.S. Pat. No. 4,794,239. Another two-dimensional symbology, known as xe2x80x9cPDF417xe2x80x9d, is described in U.S. Pat. No. 5,304,786.
Still other symbologies have been developed in which the symbol is comprised not of stacked rows, but of a matrix array made up of hexagonal, square, polygonal and/or other geometric shapes, lines, or dots. Such symbols are described in, for example, U.S. Pat. Nos. 5,2276,315 and 4,794,239. Such matrix code symbologies may include Vericode, Datacode, and MAXICODE.
Ever since the advent of the Universal Product Code in the 1970""s, linear bar code symbols have been widely adopted as an inexpensive but effective way of automating the link between printed numbers on paper and computer databases. Several bar code xe2x80x9clanguages,xe2x80x9d called xe2x80x9csymbologiesxe2x80x9d have been developed, each with its advantages for certain applications. Because bar codes are so common in our daily environment, and used in so many different applications, it is often important that a symbology, or a distinct variant of a symbology, be reserved for one specific application. For example, a bar code scanning system may read a bar code encoding a string of digits such as xe2x80x9c12345678905xe2x80x9d. It is very important that the system can unequivocally determine that this string is to be used to look up the price of a grocery item, and that the price can be found, using the decoded string of digits as a key, in a database of numbers assigned by the Uniform Code Council for this purpose. In the past, many other symbologies and symbology variants have also been reserved for such specific uses, such as a Code 128 symbol for marking medical instruments, a 14-digit Interleaved Two-of-Five symbol for marking cases for logistics tracking, and a 6-digit Code 39 symbol for marking telecommunications equipment.
One aspect held in common by all of the above traditional bar code applications, is that a worker (such as a checkout clerk at a supermarket) will be trained and paid to scan the specific kind of bar code required by the application. Recently, however, as the cost of computers, and of scanning hardware, has decreased, a new set of consumer-scanning applications has become feasible.
Consumer scanning applications will, in principle, have many requirements in common with traditional bar code applications, except that the consumer-scanning application will increase the difficulty of meeting some of these requirements. In addition, consumer scanning places some new requirements on the symbology.
Just like in traditional applications, the consumer scanning system needs the ability to distinguish bar codes for the intended application from all other bar code types. A new requirement, however, is that the consumer-as-scanner-operator needs, without training, to be able to visually distinguish the consumer bar code from the other bar codes in the environment. Also, the consumer must realize, at a glance and almost instinctively, that scanning a bar code with a certain graphical xe2x80x9cmessagexe2x80x9d will cause a specific action that is desired by the consumer. For example, a consumer bar code may have the purpose of linking a print advertisement to a specific page on the World Wide Web. The consumer bar code must be easily recognized as a bar code that will, in this example, launch a web browser program. In other words, the ideal consumer-oriented bar code must serve not only a paper-to-machine interface, but also as a graphical user interface (GUI) to the associated consumer application.
An Interface Graphic, although highly desirable in helping consumers identify the proper bar code to scan, will inevitably require some additional space (compared to a similar bar code without any Interface Graphic). Advertisers may be tempted to print the bar code minus the graphic, so that the bar code takes up less space within the advertisement. However, this will reduce consumer recognition, and reduce the overall effectiveness of the system. Thus, the ideal consumer scanning symbology would incorporate its Interface Graphic as an integral portion of the scannable symbol. In this way, the overall size of the symbol-plus-graphic can be reduced, and further, removal of the interface graphic would disable the symbol entirely (thus negating any motivation to remove it). Furthermore, it is desirable for the Interface Graphic itself to be usable in other contexts than the bar code (for example, in a corporate logo) to help reinforce the consumer""s association between the bar code and the program (web browser, etc.) for which the bar code serves as input. Thus, a preferred embodiment of the Interface Graphic would contain xe2x80x9cscannablexe2x80x9d elements, yet can also stand on its own as a graphic design.
A consumer scanning system often lacks the checks-and-balances that, in business bar coding systems, help enforce good print quality. In a business system such as retail checkout in a supermarket, or such as a shipping/receiving application, badly printed symbols impact the supermarket or receiving company as a measurable loss of productivity. As a result, it is common for business to automatically capture statistics on bar code performance, and to enforce sanctions on suppliers who do not print acceptable bar codes. In contrast, performance of consumer bar codes will not be tracked, and it is expected that they will not always be printed according to specification. One of the most common violations of bar code specifications is to reduce the required white space surrounding a bar code, in order to save space on the paper. Thus the ideal consumer scanning symbology will work with minimal amounts of white space surrounding the bar code, and preferably, the overall design of the bar code (including its Interface Graphic) will help protect the required white space from encroaching text or other graphics.
Many traditional bar code applications need to fit the printed symbols in a relatively small area. Consumer scanning applications increase the importance of this requirement, as the bar codes will need to fit in constrained spaces such as to mark line items in catalogue tables, and to fit within a single line of text in a newspaper article. Thus, the ideal consumer scanning symbology needs to minimize both the height and the length of the printed bar code, while still incorporating a distinctive GUI.
One prior art symbology, the xe2x80x9cCueCodexe2x80x9d bar code, sponsored by Digital Convergence, is an example of a new symbology (a variant of Code 128) for consumer applications that has been given a non-traditional appearance. In this case, the CueCode is always accompanied by a Digital Convergence trademark (the letter xe2x80x98Cxe2x80x99 preceded by a colon), and moreover, the bars of this bar code are always printed at a 22.5 degree slant, to help visually distinguish these symbols from other bar codes. However, these attempts to visually distinguish the CueCode have resulted in a bar code that is significantly wider than a standard Code 128 symbol encoding the same amount of data. The ideal consumer scanning symbology will provide a readily recognizable GUI, without a significant increase in size. Moreover, the techniques used by Digital Convergence for making the bar code visually distinctive are, in no way, integral to the design or scanning of the symbology. If one were to straighten up the bars, and totally remove the trademark, this would have no negative impact on the scanner""s ability to read the symbol. In fact, the opposite is true: straightening out the bars would improve scannability, and the trademark is usually printed in red ink so as to make it as invisible to the scanner as possible. Ideally, the GUI element of the consumer bar code should be an integral part of the symbology, such that removing the GUI would disable the scanner (not improve its performance).
One more aspect of CueCodes should also be noted. Two triangles are printed on the left and right sides of each CueCode. These triangles are placed so as to create 10X-wide white spaces (forming the required xe2x80x9cquiet zonesxe2x80x9d or xe2x80x9cmarginsxe2x80x9d specified for Code 128). These are somewhat similar in appearance to a technique of the present invention called a xe2x80x9cprotected marginxe2x80x9d. However, the triangles are not part of the logo or Interface Graphic portion of the CueCode, as is the xe2x80x9cprotected marginxe2x80x9d of the present invention. These triangular features of a CueCode might also be mistaken for a second technique of this invention, called a xe2x80x9ccaptured margin.xe2x80x9d CueCode""s triangles do not perform this function, however, for three reasons:
1) scans near the thin end of the triangle may not resolve the narrow tip of it (which becomes less than 1X wide), and thus not all scans will xe2x80x9cseexe2x80x9d a captured margin;
2) any scan that is not perfectly parallel to the long dimension of the CueCode, if near the top or bottom of the symbol, will miss at least one of the two triangles completely, and thus not all scans will xe2x80x9cseexe2x80x9d a captured margin; and
3) in decoding a CueCode (or in decoding standard Code 128), an exact width for the margins is not required (and, in fact, CueCodes can be scanned successfully even if the triangles are removed).
Another example in the prior art is Supercode, which is a two-dimensional bar code that can be laid out in non-rectangular shapes. Thus, it is possible to lay out a Supercode symbol in a way that suggests a graphic image. However, not only does this layout greatly reduce the spatial efficiency of the symbol (compared to a simple rectangular layout), but the resulting graphic still looks like a bar code (because it is, in fact, a bar code), and thus this format is not appropriate for corporate logos and other uses.
1. Oobjects of the Invention
It is a general object of the present invention to provide an improved bar code symbology incorporating a user recognizable graphic pattern.
It is another object of the invention to provide a bar code reader capable of reading the improved symbology.
It is a further object of the present invention to provide a printer for printing the improved symbology.
It is a still further object of the present invention to provide software capable of decoding the improved symbology.
It is an even further object of the invention to provide a method which can be used to accomplish one or more of the above objects.
It is an object of the present invention to provide a machine-readable symbology, in which consumer-friendly text and graphics may be printed in direct contact with the leftmost and rightmost bars of the symbol, and may even coincide with these leftmost and rightmost bars.
It is still another object of the present invention to provide a variable-length linear symbology that does not require large white spaces at either end of the bar code, and yet resists short-reads without needing to explicitly encode the length of the symbol.
It is an object of the present invention to provide a machine-readable symbology that includes a space-efficient xe2x80x9cfinderxe2x80x9d pattern, which facilitates a rapid search through text and graphics without the need to perform arithmetic upon sums of multiple bars and spaces.
It is a goal of the present invention to provide a machine-readable symbology, in which consumer-friendly text and graphics are printed in direct association with the bars and spaces of the symbol, and may even coincide with some of these bars and spaces.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, where the Interface Graphic cannot be removed without disabling the symbology.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, and that conserves space by combining elements of the bar code with elements of the Interface Graphic.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, and that can use measurements that span both vertical and non-vertical edges as part of recognition patterns.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, where the Interface Graphic helps define and protect the required white space (xe2x80x9cmarginsxe2x80x9d) around the symbol.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, where the Interface Graphic extends above and below the bars of the symbol, in order to define a taller image rectangle that protects the required white space (xe2x80x9cmarginsxe2x80x9d) above and below the symbol.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, where all or part of the Interface Graphic also serves as a xe2x80x9cfinder patternxe2x80x9d for the symbol.
It is a goal of the present invention to provide a machine-readable symbology, which incorporates an Interface Graphic element designed for easy human recognition, where all or part of the Interface Graphic also serves as all or part of a xe2x80x9cstart patternxe2x80x9d for the symbol.
Additional objects, advantages and novel features of the present invention will become apparent to those skilled in the art from this disclosure, including the following detailed description, as well as by practice of the invention. While the invention is described below with reference to preferred embodiments, it should be understood that the invention is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional applications, modifications and embodiments in other fields, which are within the scope of the invention as disclosed and claimed herein and with respect to which the invention could be of significant utility.
2. Summary of the Invention
The present invention provides a bar code symbology comprising symbols including characters having patterns of bars and spaces. Each character spans a distance of m module widths and is represented by n bars and p interleaved spaces. The largest single bar or space is limited to k modules in width. Each symbol has a predetermined start pattern, a predetermined stop pattern, and a human recognizable graphic element provided among the patterns of bars and spaces. At least a portion of the graphic element is machine readable and recognizable by a decoder as a portion of a respective symbol.
The present invention further provides an information-bearing machine-readable carrier including a substrate; and a symbol including characters having a pattern of bars and spaces on the substrate in which each character spans a distance of m module widths and is represented by n bars and p interleaved spaces. The largest single bar or space in a character is limited to k modules in width. The symbol has a predetermined start pattern, a predetermined stop pattern, and a human recognizable graphic element provided among the pattern of bars and spaces, with at least a portion of the graphic element being machine readable and recognizable by a decoder as a portion of the symbol.
The present invention further provides an imager or a scanner for obtaining data from a target in a field. The target includes a symbol including characters having a pattern of bars and spaces in which each character spans a distance of m module widths and is represented by n bars and p interleaved spaces. The largest single bar or space in a character is limited to k modules in width. The symbol has a predetermined start pattern and a human recognizable graphic element provided among the pattern of bars and spaces, with at least a portion of the graphic element being machine readable and recognizable by a decoder as a portion of the symbol. The decoder is operative for processing image data to derive information contained in the symbol.
The novel features and characteristics of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to a detailed description of specific embodiments, when read in conjunction with the accompanying drawings.